The use of screen assemblies is well known. For example, assemblies including one or more cylindrical screen jackets disposed over perforated based pipes are commonly used in downhole petroleum production operations. Often, the screen jacket is formed with wire wrapped around elongated, axially-oriented rib members. The spaces between adjacent wire wraps allow permitted flow through the screen jacket. In some applications, the screen jacket assists in holding gravel packing in the hole or casing. In other applications, such as open-hole completions, the screen jacket may be used to directly hold back the formation. Thus, in these examples, the size of the spaces between wire wraps in the screen jacket is typically critical for effective operation. Furthermore, these screen assemblies may be subject to substantial loads and stresses during use. Accordingly, the robustness of the screen jacket and positioning of the screen jacket relative to the base pipe is also often critical for effective operation.
Various types of screen assemblies have been used. For the cylindrical-type screen assemblies referenced above, for example, the screen jacket may be formed or wrapped directly onto the base pipe in a large screen assembly machine. Various challenges exist with this method. For example, maintaining the proper orientation and preventing bowing of the pipe during the screen wrapping operation may be difficult. This challenge is common, in particular, where the base pipe is not perfectly straight or round or is very large (e.g. length of 40′ at over 20 lbs/ft). Consequently, it may be difficult to form the wire wraps with the necessary precise spacing. Furthermore, this assembly technique may be slow and cause substantial wear to the screen assembly machine.
For another example, the screen jacket may be formed with an inner diameter that is larger than the outer diameter of the base pipe, allowing the screen jacket to be slid over and welded to the base pipe. With this technique, a gap exists between the screen jacket and base pipe. During deployment and use, the screen member could buckle, collapse or deform into the gap. Further, each weld may be subject to fail or give out, causing the screen to move relative to, or disconnect from, the base pipe.
It should be understood that the above-described examples, features and/or disadvantages are provided for illustrative purposes only and are not intended to limit the scope or subject matter of the claims of this patent application or any patent or patent application claiming priority hereto. Thus, none of the appended claims or claims of any related application or patent should be limited by the above discussion or construed to address, include or exclude the cited examples, features and/or disadvantages, except and only to the extent as may be expressly stated in a particular claim.
Accordingly, there exists a need for a screen assembly and methods of manufacture thereof having one or more of the following attributes, capabilities or features: involves heat shrinking the screen jacket onto the base pipe; ensures accurate and/or consistent spacing between wire wraps of the screen jacket; maintains good slot tolerances on the screen jacket; eliminates or minimizes any gap between the screen jacket and the base pipe; provides a tight, firm and/or reliable fit of the screen jacket to the base pipe along the entire length of the screen jacket; provides an interference fit between the screen jacket and base pipe; includes a screen assembly that is robust; includes a base pipe and screen jacket arrangement that essentially acts as a single unit during operations; includes a screen jacket that is resistant to collapsing or deforming during use; includes a screen jacket that is substantially resistant to typical loads transmitted thereto; includes a screen jacket that is resistant to undesirable shifting relative to, or separation from, the base pipe during use; eliminates, reduces or minimizes the use of welds to connect the screen jacket and base pipe; involves an assembly process that is simple, quick and/or efficient and minimizes wear upon screen assembly machines; or a combination thereof.